Hydraulic brake



March 20, 1928. 1,663,147

c. A. sPoTz HYDRAULIC BRAKE Filed April 16, 1926 gwoe'nlfoz ('kesir A. 5 00 Z:

2 Sheets-Sheet 1 March 20, 1928." 1,663,147

C. A. SPOTZ HYDRAULIC BRAKE Filed April 16, 1926 2 Sheets-Sheet 2 gmmtoz mesiemz'. s ozz a 1 'lhezinvention has,

provide a there will be no dangerof from excessive l With these and otherobgects 1n v1ew,the

of parts hereinafter described, my

view of a modification.

extension to the other wheels would hence need no l CMy present-invention relates to improvelnents iirso-called hydraulic brakes of the type commonly employed on motor vehicles provided with four wheel brakes.

among itsobjects, to brake of this character which wil be proof against leakage and yet be free from the necessityof providing packing such as is necessary where moving pistons are em- 10 ployed; to secure adequate brake shoe clearance without detracting from efliclent braking action; to provide a'construction which will be free froma'll danger-0f detrimental action of dust-and mud; and'one in which damage of parts pressure on the foot lever.

invention includes'the novel features of construction and arrangement and combination said invention being defined and ascertained by the claim appended hereto. I An embodiment of the invention is illustrated in the accompanying drawings, in

25 hie11:"-- y 1 Fi 1 is side elevation, partly n section, showing a brake 'drumwith associated brake shoes and cooperating" parts.

Figure 2 is a section on line 2-2 of Fig.

30 l ,"'but'showing in addition'and diagrammatically,

itsoperating lever the master bellows, and'p'ipe connection, the external emergency brake band being omitted from Fig. 1, for convenience of illustration; Figure 3 is a In these drawings I have shown the brake in connection with the drum of one wheel only and that one of the rear wheels, this being for simplicity of illustration, as its the art. The axle 2, wheel 3 and brake be representative of form, an

vious to one skilled in shown at 1, axlehousing drum 4, are intended to the customary or any desired specific description, an

brake drum may be provided with the customary external hand brake 5 which may be used for emergency purposes.

The axle hOllSlIW' carries a ri id disc 6, to

which are secured bracket mem ers 7 lying within the space defined by the drum, and each of which in turn carries an expansible metal bellows 8 of the type known as a sylphon.- To the head member 8 of each bellows is pivotally connected, at 9 the movable I guided by be ob-- d bracket 16, which d the orenn'nnwrcn, commences.

App1ication filed April 16, 1926.- Serial no. 102,563.

and bellows are IOVIdGd,

symmetrically disposed about the w eelaxis,

and the shoes are held properly spaced and brackets 12 secured to the disc 6 and having radial webs or flanges 12 1 ing between the adjacent ends of the brakes oes. Brackets 12 are provided with lugs 12 against which the inner faces of the ends or the shoes abut when drawn inward, to limit such inward movement and hold them truly concentric to the drums and spaced therefrom at all points whereby rubbing is prevented) In'order that the brake shoes maybe read ily relined when worn, brackets 12 are pro-' vided with plate members 12" removably secured thereto by screws c, which plates overlie the ends of the brake shoes and hold them normally in position. By removing the plates 12 and the pins 10 the-shoe'smay be readily slipped out and the worn brake'lining or facing repl.aced. 1 1

The brake shoes may be of metal provided with any suitable brake surface material- 11 andas no bending is necessary, of brake bands, they ma be formed 'on a curve corresponding exactly to the curvature of the inner periphery of the drum, and be braced against distortion by the webs 11.

The bracket members 7 are provided with ports or passages 7 a which communicate with the interior-of the bellows and are connected to each other by the pipes 13, the port 7 of one of the brackets being connected by a pipe 14 with the stationary element or base 15 of a master bellows 15 carried by a floor of the auto adjacent The movable element 15" guided by posts placed under the the drivers seat. is provided with a rod 15 or standards 16.

Rod 15 has fast thereon spaced apart collars 15 and 15 and a slidable collar 15 between which and the collar 15 and encircling the rod is a compression spring 20. A foot lever 21 fulcrumed 22 has a depending arm 21 provided with a 'slot or opening to receive the rod 15, the

suitable in practice would be on a fixed pivotas in the case portion of; the arm lying between the collars and 15 and going preferably provided with oss a lar 15'. v

The lower end of the arm 21" is connected y a tension spring 23 with a fixed abutment 24 which, when pressure on the brake pedal is removed, tends to return said lever to initial position and also, by arm 21" acting on collar 15' toextend the bellows 15.

Pressureon the brake pedal compresses spring and transmits movement to the rod 15 but the strength of sprin 20 is to be made such that overloading of t e master bellows 1 5 will be impossible, and hence all danger of its rupture avoided.

It will thus be seen that when pressure is applied to the foot lever the master bellows will be collapsed, which will cause the contained fluid (which fills the entire system and is usually oil or other non-congealable liquid) to be forced into the bellows 8 where by all the latter are simultaneously expanded and the shoes forced outward into contact with the brake drum. On release of the brake pedal, spring 23 extends the master ellows which withdraws liquid from all the bellows 8 and produces suction therein which in turn draws all the brake shoes inward until they are sustained by lugs 12".

emg positively held against these, no rubbing or dragging of the brake surfaces is possible and rattling is prevented.

It will be observed that the brake shoes and their operating bellows and connections are wholly enclosed and hence protected from, dust, mud, etc.

Instead of us' g the form of operating device shown in Figs. 1 and 2, I may use the form shown in Fig. 3.

In this the brake pedal lever 21" is articulated on a fixed pivot'22 and is connected by a spring 25 with the upper arm of a two adjacent the opening a rounded. for contact with the slidable col-' in series so as to be said ivot 22' armed lever- 26 fu'lcrumed on he lower independently of the pedal lever. arm of said two armed by a link 27 with the rod 150f the master bellows.

Said lower arm of lever 26 is also connected by a spring 27 with a fixed abutment 28 which tends to extend the master bellows when pressure on the brake pedal is removed.

Spring 25 is made of greater strength than spring 27 so that its tension, when pedal lever 21 is operated, will collapse the master bellows against the tension of spring 27', but the strength of spring 25 is such thalt rupture of the bellows will not be pos- SI e. I

Having thus described my invention, what I claim is In a brake mechanism for a brake drum and axle housing, a disc member carried by the housing and closin the open side of the drum, a plurality o arcs aped radially movable brake shoes within motor vehicles,

the drum, brackets mounted on said disc between said shoes, said brackets being adapted to guide said shoes and to limit their inward movement, plates removably mounted one. on each bracket to normally 'hold the shoes against axial movement in the drum, a plurality of expansible metal bellows carried by said disc, onefor each shoe, a plurality of levers each mounted at one of its ends on. a fixed pivot on said disc, and each con-' nected at its other end to one of said bellows, a plurality of links each swivelly connected at one end to an intermediate portion of a lever and swivelly connected at the other end to a shoe, said'bellows being connected simultaneously operable by' fluid pressure. 4

In testlmony whereof I 'aflix my signature.-

CHESTER A. SPOTZ.

lever 26 is connected 

